He will be sentenced in January, receiving a prison term worked out in a plea bargain. As part of the deal, the 37-year-old father of two also agreed to cooperate with investigators in the continuing probe.

"Mr. Rusnak undertook a sustained and concentrated effort to avoid the bank's accountability system, and whether he had help in that at this time has not been determined," U.S. Attorney Thomas DiBiagio said.

Rusnak was indicted in June in the biggest bank fraud case since Nick Leeson lost more than $1 billion on futures trades and caused the 1995 collapse of England's distinguished Barings Bank.

Rusnak ran up the losses at Allfirst Financial over five years, mostly from trading Japanese yen. While trying to recoup those losses, prosecutors say, he dug himself a deeper hole by taking ever-larger risks.

Prosecutors said Rusnak did not directly profit from the trading losses, but by manipulating Allfirst's computerized system of tracking trades, he was able to make it look as if the bank was making money instead of losing it between 1997 and 2001.

That earned Rusnak bonuses of more than $650,000. He collected about $433,000 of that before the fraud was discovered last winter. Whether Rusnak will pay anything to Allfirst will be determined at a court hearing in January.

Rusnak could have gotten up to 30 years in prison and a $1 million fine. Still, the federal prosecutor said the 71/2-year sentence, plus five years' probation after release, is stiff for white-collar crime.

Leeson served 31/2 years in the Barings case. That scandal prompted banks worldwide to tighten internal checks, and Leeson expressed surprise earlier this year that the problems at Allfirst were not discovered sooner.

Allfirst was under parent company Allied Irish Banks at the time Rusnak worked there. Last month, AIB, based in Dublin, announced a proposal to sell Allfirst to Buffalo, N.Y.-based M&T Bank Corp. for about $3.1 billion. AIB denied the scandal had anything to do with the sale.